The present invention is concerned with the handling of can ends in a downstacker that restricts the rotation of the can ends in a downstacker that feeds can ends into a compound liner apparatus, a conversion press, an end seaming apparatus or offline test equipment for further processing. Can ends can be lids in a two piece can, lids and bottoms in a three piece can or bottoms of a two piece can with a screw cap on the other end. Typically, can ends are supplied in sticks consisting of a stack of can ends that are placed in a downstacker and are individually fed from the bottom of the downstacker onto a starwheel of the compound liner apparatus, conversion press, end seaming apparatus or offline test equipment for further processing. An example of a downstacker that contains a stack of can ends can be seen in U.S. Pat. No. 5,476,362.
A continuing problem that can be encountered in the handling of can ends in a downstacker is that rotational movement of the feed screws in the compound liner apparatus, conversion press, end seaming apparatus or offline test equipment can cause the can ends in the downstacker to rotate. Rotational movement of the can ends relative to each other can cause abrasion on the surface of the can ends. Abrasion of the can ends could lead to the build up of wear debris from the abraded can end that could contaminate the contents of a beverage or food container and lead to the accumulation of wear debris in the compound liner apparatus, conversion press, end seaming apparatus or offline test equipment. The accumulated debris in these machines must eventually be removed in a time consuming cleansing operation of the machinery that would cause production line down time. Additionally, abraded or scratched can ends are not aesthetically pleasing to an end user customer purchasing a beverage or food container because end user customers expect a beverage or food container to not be damaged. Abraded or scratched can ends are particularly unattractive in the case of colored ends. Thus, a need exists in the art to provide an apparatus that restricts the rotation of can ends in a downstacker.